Renamed GetSecret to GetSecretWord.
Made integration test assertions more readable by using nunit 'Assert.That'.
Nunit-ified all assertions for hosted payments.
Nunit-ified all assertions for order building and validation.
Nunit-ified the assertions for all the remaining unit tests.
Null reference fix for missing customer details in hosted order and various minor refactors.
Small change or wording and other tiny fixes.
Merge branch 'feature/pre-release-refactoring' into develop